I've just opened a new Chrome browser which loaded up the usual websites I have set to open on start-up; however Avast keeps popping up the below:

It seems to be related to Tumblr, yet I can easily browse it so not sure what it is that it's blocking - I do have the reworked xKit that allows for changes etc. to Tumblr but again can still access that. Is there anyway I can stop this pop-up from appearing as it's annoying.